Video-assisted thoracoscopic surgery versus open lobectomy for stage I lung cancer: a meta-analysis of long-term outcomes

Li Z, Liu H, Li L

CRD summary

The authors concluded that video-assisted thoracoscopic surgery was superior to open lobectomy, in five-year overall survival, for patients with stage I lung cancer, but the findings should be carefully interpreted due to the low level of evidence. Despite some limitations (non-randomised controlled trials, and unknown comparability of groups), their cautious conclusion appears to be reliable.

Authors' objectives

To compare video-assisted thoracoscopic surgery and open lobectomy, for the treatment of stage I lung cancer.

Searching

MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL) and EMBASE were searched, up to July 2011, for studies published in English. Search terms were reported.

Study selection

Clinical trials that compared video-assisted thoracoscopic surgery with open lobectomy, in patients with clinical or pathological stage I lung cancer, were eligible for inclusion. Patients had to have no extrapulmonary metastasis, no previous treatment for lung cancer, and no previous or simultaneous malignancies. They had to have good lung function and be able to tolerate open lobectomy. Trials of patients with unresectable lung cancer or recurrent disease after lobectomy were excluded. The treatment groups had to have similar baseline patient characteristics.

Included trials were conducted in Japan, China or the USA. Where reported, the mean age of patients ranged from 62 to 67.7 years, and 56% of them were male. Some trials included patients with stage IA cancer, and others included patients with stages IA or IB. All trials reported the clinical or pathologic stage of lung cancer.

The authors did not state how many reviewers were involved in study selection.

Assessment of study quality

Three reviewers independently evaluated trial quality, but the criteria assessed were not reported.

Data extraction

The data were extracted to calculate odds ratios, with 95% confidence intervals. The outcomes of interest included overall survival, local recurrence rates, systemic recurrence rates, and complications. Three reviewers independently extracted the data.

Methods of synthesis

Pooled odds ratios and 95% confidence intervals were calculated, using both random-effects and fixed-effect models. If the results did not differ between the two models, the random-effects results were reported. Heterogeneity was assessed using Χ² and Ι². Ι² values of less than 25% were considered low and values greater than 50% were considered high. Publication bias was assessed in funnel plots.

Results of the review

Nine controlled trials (eight non-randomised and one randomised) were included in the review (1,362 participants). The median follow-up ranged from 4.6 months to 68.1 months.

Overall survival: This was significantly longer for patients who had video-assisted thoracoscopic surgery than for those who had open lobectomy, at five years (OR 2.01, 95% CI 1.44 to 2.78; Ι²=17%; eight trials), but no statistically significant difference was found at one year (two trials) and at three years (two trials). The funnel plot for five-year survival revealed potential publication bias.

Other outcomes: There was no statistically significant difference in local recurrence between video-assisted thoracoscopic surgery and open lobectomy (six trials). Systemic recurrence was significantly lower with video-assisted thoracoscopic surgery (OR 0.52, 95% CI 0.29 to 0.90; Ι²=0; five trials). The complication rate was significantly lower with video-assisted thoracoscopic surgery (OR 0.36, 95% CI 0.23 to 0.57; Ι²=59%; three trials); heterogeneity was significant. Three trials reported that pathological disease in lymph nodes (N1 and N2) was found, in both groups, after surgery, with no significant difference between groups.

Authors' conclusions

Video-assisted thoracoscopic surgery was superior to open lobectomy, in five-year overall survival, for patients with stage I lung cancer. The findings should be carefully interpreted due to the low level of evidence.

CRD commentary

The review addressed a clear question and was supported by appropriate inclusion criteria. Relevant databases were searched for trials published in English. No specific attempts to identify unpublished studies were reported, so relevant studies may have been missed. Appropriate methods to reduce reviewer error and bias were used for data extraction and quality assessment, but it was unclear whether similar methods were used in study selection. The authors stated that overall level of clinical evidence was low, but the quality details for the included trials were not reported. Appropriate methods were used to pool the data, but the reasons for statistical heterogeneity in the complication rate were not investigated. The authors noted the limitations of their review, which were the small samples, low level of clinical evidence, and publication bias.

Given that most of the trials were not randomised, and the unknown comparability of the treatment groups, the authors' conclusion that their findings should be interpreted with caution appears to be reliable.

Implications of the review for practice and research

Practice: The authors stated that video-assisted thoracoscopic lobectomy was a beneficial alternative to open lobectomy, for selected patients with pulmonary lesions, and it should be promoted even though the procedure was more complex.

Research: The authors stated that further randomised controlled trials were needed to clarify the value of video-assisted thoracoscopic surgery, compared with open lobectomy, for stage I lung cancer.

Funding

Funded by the National Natural Science Foundation of China, and the Liao Ning BaiQianWan Talents Program.

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.